the present invention relates to a drop-out detector circuits, and in particular to drop-out detector circuit in a device for playing back recorded data which processes a signal by digitizing a high-frequency signal component produced by reading a recording medium.
In the prior art, playback systems for reproducing recorded data, for example disc players for video discs prerecorded with FM-modulated image signals, usually employ an analog system for processing the FM image signals from the disc.
However, in view of the increased use of integrated circuits, there are many advantages to using digital rather than analog processing. In order to allow greater functional diversity in the procession of signals and to achieve better picture quality, the applicant has previously proposed (see Japanese Patent Application No. 60-280711) a playback apparatus for recorded data which digitally processes signals read out from a disc.
However, in a playback apparatus for recorded data such as a video disc player the presence of dirt or damage to the recording medium causes gaps, i.e., drop-out, in the signal read out from the recording medium. It is necessary to detect and compensate for these drop-outs. Many types of circuits for detecting drop-out in analog-processing playback devices are known in the prior art, but all require the use of separate circuitry.